]> granicus.if.org Git - imagemagick/blobdiff - magick/quantize.c
(no commit message)
[imagemagick] / magick / quantize.c
index 45c7ab15968e5907ea085d3aaad9bdef3ec3b331..1282f9159b51418bdc973495ffb5647b5f498495 100644 (file)
@@ -17,7 +17,7 @@
 %                              July 1992                                      %
 %                                                                             %
 %                                                                             %
-%  Copyright 1999-2010 ImageMagick Studio LLC, a non-profit organization      %
+%  Copyright 1999-2011 ImageMagick Studio LLC, a non-profit organization      %
 %  dedicated to making software imaging solutions freely available.           %
 %                                                                             %
 %  You may not use this file except in compliance with the License.  You may  %
 #include "magick/quantize.h"
 #include "magick/quantum.h"
 #include "magick/string_.h"
+#include "magick/thread-private.h"
 \f
 /*
   Define declarations.
 */
+#if !defined(__APPLE__) && !defined(TARGET_OS_IPHONE)
 #define CacheShift  2
+#else
+#define CacheShift  3
+#endif
 #define ErrorQueueLength  16
 #define MaxNodes  266817
 #define MaxTreeDepth  8
@@ -362,7 +367,7 @@ MagickExport QuantizeInfo *AcquireQuantizeInfo(const ImageInfo *image_info)
   QuantizeInfo
     *quantize_info;
 
-  quantize_info=(QuantizeInfo *) AcquireAlignedMemory(1,sizeof(*quantize_info));
+  quantize_info=(QuantizeInfo *) AcquireMagickMemory(sizeof(*quantize_info));
   if (quantize_info == (QuantizeInfo *) NULL)
     ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
   GetQuantizeInfo(quantize_info);
@@ -485,26 +490,6 @@ static MagickBooleanType AssignImageColors(Image *image,CubeInfo *cube_info)
   ssize_t
     y;
 
-  MagickBooleanType
-    proceed;
-
-  RealPixelPacket
-    pixel;
-
-  register ssize_t
-    i,
-    x;
-
-  register const NodeInfo
-    *node_info;
-
-  ssize_t
-    count;
-
-  size_t
-    id,
-    index;
-
   /*
     Allocate image colormap.
   */
@@ -532,40 +517,75 @@ static MagickBooleanType AssignImageColors(Image *image,CubeInfo *cube_info)
     (void) DitherImage(image,cube_info);
   else
     {
+      CacheView
+        *image_view;
+
       ExceptionInfo
         *exception;
 
-      CacheView
-        *image_view;
+      MagickBooleanType
+        status;
 
+      status=MagickTrue;
       exception=(&image->exception);
       image_view=AcquireCacheView(image);
+#if defined(MAGICKCORE_OPENMP_SUPPORT)
+      #pragma omp parallel for schedule(dynamic,4) shared(status)
+#endif
       for (y=0; y < (ssize_t) image->rows; y++)
       {
+        CubeInfo
+          cube;
+
         register IndexPacket
           *restrict indexes;
 
         register PixelPacket
           *restrict q;
 
+        register ssize_t
+          x;
+
+        ssize_t
+          count;
+
+        if (status == MagickFalse)
+          continue;
         q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
           exception);
         if (q == (PixelPacket *) NULL)
-          break;
+          {
+            status=MagickFalse;
+            continue;
+          }
         indexes=GetCacheViewAuthenticIndexQueue(image_view);
+        cube=(*cube_info);
         for (x=0; x < (ssize_t) image->columns; x+=count)
         {
+          RealPixelPacket
+            pixel;
+
+          register const NodeInfo
+            *node_info;
+
+          register ssize_t
+            i;
+
+          size_t
+            id,
+            index;
+
           /*
             Identify the deepest node containing the pixel's color.
           */
           for (count=1; (x+count) < (ssize_t) image->columns; count++)
             if (IsSameColor(image,q,q+count) == MagickFalse)
               break;
-          AssociateAlphaPixel(cube_info,q,&pixel);
-          node_info=cube_info->root;
+          AssociateAlphaPixel(&cube,q,&pixel);
+          node_info=cube.root;
           for (index=MaxTreeDepth-1; (ssize_t) index > 0; index--)
           {
-            id=ColorToNodeId(cube_info,&pixel,index);
+            id=ColorToNodeId(&cube,&pixel,index);
             if (node_info->child[id] == (NodeInfo *) NULL)
               break;
             node_info=node_info->child[id];
@@ -573,32 +593,41 @@ static MagickBooleanType AssignImageColors(Image *image,CubeInfo *cube_info)
           /*
             Find closest color among siblings and their children.
           */
-          cube_info->target=pixel;
-          cube_info->distance=(MagickRealType) (4.0*(QuantumRange+1.0)*
+          cube.target=pixel;
+          cube.distance=(MagickRealType) (4.0*(QuantumRange+1.0)*
             (QuantumRange+1.0)+1.0);
-          ClosestColor(image,cube_info,node_info->parent);
-          index=cube_info->color_number;
+          ClosestColor(image,&cube,node_info->parent);
+          index=cube.color_number;
           for (i=0; i < (ssize_t) count; i++)
           {
             if (image->storage_class == PseudoClass)
               indexes[x+i]=(IndexPacket) index;
-            if (cube_info->quantize_info->measure_error == MagickFalse)
+            if (cube.quantize_info->measure_error == MagickFalse)
               {
                 q->red=image->colormap[index].red;
                 q->green=image->colormap[index].green;
                 q->blue=image->colormap[index].blue;
-                if (cube_info->associate_alpha != MagickFalse)
+                if (cube.associate_alpha != MagickFalse)
                   q->opacity=image->colormap[index].opacity;
               }
             q++;
           }
         }
         if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
-          break;
-        proceed=SetImageProgress(image,AssignImageTag,(MagickOffsetType) y,
-          image->rows);
-        if (proceed == MagickFalse)
-          break;
+          status=MagickFalse;
+        if (image->progress_monitor != (MagickProgressMonitor) NULL)
+          {
+            MagickBooleanType
+              proceed;
+
+#if defined(MAGICKCORE_OPENMP_SUPPORT)
+            #pragma omp critical (MagickCore_AssignImageColors)
+#endif
+            proceed=SetImageProgress(image,AssignImageTag,(MagickOffsetType) y,
+              image->rows);
+            if (proceed == MagickFalse)
+              status=MagickFalse;
+          }
       }
       image_view=DestroyCacheView(image_view);
     }
@@ -613,6 +642,9 @@ static MagickBooleanType AssignImageColors(Image *image,CubeInfo *cube_info)
       register PixelPacket
         *restrict q;
 
+      register ssize_t
+        i;
+
       /*
         Monochrome image.
       */
@@ -717,9 +749,6 @@ static MagickBooleanType ClassifyImageColors(CubeInfo *cube_info,
   CacheView
     *image_view;
 
-  ssize_t
-    y;
-
   MagickBooleanType
     proceed;
 
@@ -736,13 +765,14 @@ static MagickBooleanType ClassifyImageColors(CubeInfo *cube_info,
     pixel;
 
   size_t
-    count;
-
-  size_t
+    count,
     id,
     index,
     level;
 
+  ssize_t
+    y;
+
   /*
     Classify the first cube_info->maximum_colors colors to a tree depth of 8.
   */
@@ -786,7 +816,7 @@ static MagickBooleanType ClassifyImageColors(CubeInfo *cube_info,
       /*
         Start at the root and descend the color cube tree.
       */
-      for (count=1; (x+count) < image->columns; count++)
+      for (count=1; (x+(ssize_t) count) < (ssize_t) image->columns; count++)
         if (IsSameColor(image,p,p+count) == MagickFalse)
           break;
       AssociateAlphaPixel(cube_info,p,&pixel);
@@ -875,7 +905,7 @@ static MagickBooleanType ClassifyImageColors(CubeInfo *cube_info,
       /*
         Start at the root and descend the color cube tree.
       */
-      for (count=1; (x+count) < image->columns; count++)
+      for (count=1; (x+(ssize_t) count) < (ssize_t) image->columns; count++)
         if (IsSameColor(image,p,p+count) == MagickFalse)
           break;
       AssociateAlphaPixel(cube_info,p,&pixel);
@@ -914,7 +944,7 @@ static MagickBooleanType ClassifyImageColors(CubeInfo *cube_info,
         if (cube_info->associate_alpha != MagickFalse)
           error.opacity=QuantumScale*(pixel.opacity-mid.opacity);
         node_info->quantize_error+=sqrt((double) (count*error.red*error.red+
-          count*error.green*error.green+error.blue*error.blue+
+          count*error.green*error.green+count*error.blue*error.blue+
           count*error.opacity*error.opacity));
         cube_info->root->quantize_error+=node_info->quantize_error;
         index--;
@@ -973,7 +1003,7 @@ MagickExport QuantizeInfo *CloneQuantizeInfo(const QuantizeInfo *quantize_info)
   QuantizeInfo
     *clone_info;
 
-  clone_info=(QuantizeInfo *) AcquireAlignedMemory(1,sizeof(*clone_info));
+  clone_info=(QuantizeInfo *) AcquireMagickMemory(sizeof(*clone_info));
   if (clone_info == (QuantizeInfo *) NULL)
     ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
   GetQuantizeInfo(clone_info);
@@ -1056,26 +1086,26 @@ static void ClosestColor(const Image *image,CubeInfo *cube_info,
       q=(&cube_info->target);
       alpha=1.0;
       beta=1.0;
-      if (cube_info->associate_alpha == MagickFalse)
+      if (cube_info->associate_alpha != MagickFalse)
         {
           alpha=(MagickRealType) (QuantumScale*GetAlphaPixelComponent(p));
           beta=(MagickRealType) (QuantumScale*GetAlphaPixelComponent(q));
         }
       pixel=alpha*p->red-beta*q->red;
       distance=pixel*pixel;
-      if (distance < cube_info->distance)
+      if (distance <= cube_info->distance)
         {
           pixel=alpha*p->green-beta*q->green;
           distance+=pixel*pixel;
-          if (distance < cube_info->distance)
+          if (distance <= cube_info->distance)
             {
               pixel=alpha*p->blue-beta*q->blue;
               distance+=pixel*pixel;
-              if (distance < cube_info->distance)
+              if (distance <= cube_info->distance)
                 {
                   pixel=alpha-beta;
                   distance+=pixel*pixel;
-                  if (distance < cube_info->distance)
+                  if (distance <= cube_info->distance)
                     {
                       cube_info->distance=distance;
                       cube_info->color_number=node_info->color_number;
@@ -1346,6 +1376,67 @@ MagickExport QuantizeInfo *DestroyQuantizeInfo(QuantizeInfo *quantize_info)
 %
 */
 
+static RealPixelPacket **DestroyPixelThreadSet(RealPixelPacket **pixels)
+{
+  register ssize_t
+    i;
+
+  assert(pixels != (RealPixelPacket **) NULL);
+  for (i=0; i < (ssize_t) GetOpenMPMaximumThreads(); i++)
+    if (pixels[i] != (RealPixelPacket *) NULL)
+      pixels[i]=(RealPixelPacket *) RelinquishMagickMemory(pixels[i]);
+  pixels=(RealPixelPacket **) RelinquishMagickMemory(pixels);
+  return(pixels);
+}
+
+static RealPixelPacket **AcquirePixelThreadSet(const size_t count)
+{
+  RealPixelPacket
+    **pixels;
+
+  register ssize_t
+    i;
+
+  size_t
+    number_threads;
+
+  number_threads=GetOpenMPMaximumThreads();
+  pixels=(RealPixelPacket **) AcquireQuantumMemory(number_threads,
+    sizeof(*pixels));
+  if (pixels == (RealPixelPacket **) NULL)
+    return((RealPixelPacket **) NULL);
+  (void) ResetMagickMemory(pixels,0,number_threads*sizeof(*pixels));
+  for (i=0; i < (ssize_t) number_threads; i++)
+  {
+    pixels[i]=(RealPixelPacket *) AcquireQuantumMemory(count,
+      2*sizeof(**pixels));
+    if (pixels[i] == (RealPixelPacket *) NULL)
+      return(DestroyPixelThreadSet(pixels));
+  }
+  return(pixels);
+}
+
+static inline ssize_t CacheOffset(CubeInfo *cube_info,
+  const RealPixelPacket *pixel)
+{
+#define RedShift(pixel) (((pixel) >> CacheShift) << (0*(8-CacheShift)))
+#define GreenShift(pixel) (((pixel) >> CacheShift) << (1*(8-CacheShift)))
+#define BlueShift(pixel) (((pixel) >> CacheShift) << (2*(8-CacheShift)))
+#define AlphaShift(pixel) (((pixel) >> CacheShift) << (3*(8-CacheShift)))
+
+  ssize_t
+    offset;
+
+  offset=(ssize_t)
+    (RedShift(ScaleQuantumToChar(ClampToUnsignedQuantum(pixel->red))) |
+    GreenShift(ScaleQuantumToChar(ClampToUnsignedQuantum(pixel->green))) |
+    BlueShift(ScaleQuantumToChar(ClampToUnsignedQuantum(pixel->blue))));
+  if (cube_info->associate_alpha != MagickFalse)
+    offset|=AlphaShift(ScaleQuantumToChar(ClampToUnsignedQuantum(
+      pixel->opacity)));
+  return(offset);
+}
+
 static MagickBooleanType FloydSteinbergDither(Image *image,CubeInfo *cube_info)
 {
 #define DitherImageTag  "Dither/Image"
@@ -1356,66 +1447,84 @@ static MagickBooleanType FloydSteinbergDither(Image *image,CubeInfo *cube_info)
   ExceptionInfo
     *exception;
 
-  ssize_t
-    u,
-    v,
-    y;
-
   MagickBooleanType
-    proceed;
+    status;
 
   RealPixelPacket
-    color,
-    *current,
-    pixel,
-    *previous,
-    *scanlines;
-
-  register CubeInfo
-    *p;
+    **pixels;
 
-  size_t
-    index;
+  ssize_t
+    y;
 
   /*
     Distribute quantization error using Floyd-Steinberg.
   */
-  scanlines=(RealPixelPacket *) AcquireQuantumMemory(image->columns,
-    2*sizeof(*scanlines));
-  if (scanlines == (RealPixelPacket *) NULL)
+  pixels=AcquirePixelThreadSet(image->columns);
+  if (pixels == (RealPixelPacket **) NULL)
     return(MagickFalse);
-  p=cube_info;
   exception=(&image->exception);
+  status=MagickTrue;
   image_view=AcquireCacheView(image);
   for (y=0; y < (ssize_t) image->rows; y++)
   {
+    const int
+      id = GetOpenMPThreadId();
+
+    CubeInfo
+      cube;
+
+    RealPixelPacket
+      *current,
+      *previous;
+
     register IndexPacket
       *restrict indexes;
 
+    register PixelPacket
+      *restrict q;
+
     register ssize_t
-      i,
       x;
 
-    register PixelPacket
-      *restrict q;
+    size_t
+      index;
 
+    ssize_t
+      v;
+
+    if (status == MagickFalse)
+      continue;
     q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
     if (q == (PixelPacket *) NULL)
-      return(MagickFalse);
+      {
+        status=MagickFalse;
+        break;
+      }
     indexes=GetCacheViewAuthenticIndexQueue(image_view);
-    current=scanlines+(y & 0x01)*image->columns;
-    previous=scanlines+((y+1) & 0x01)*image->columns;
+    cube=(*cube_info);
+    current=pixels[id]+(y & 0x01)*image->columns;
+    previous=pixels[id]+((y+1) & 0x01)*image->columns;
     v=(ssize_t) ((y & 0x01) ? -1 : 1);
     for (x=0; x < (ssize_t) image->columns; x++)
     {
+      RealPixelPacket
+        color,
+        pixel;
+
+      register ssize_t
+        i;
+
+      ssize_t
+        u;
+
       u=(y & 0x01) ? (ssize_t) image->columns-1-x : x;
-      AssociateAlphaPixel(cube_info,q+u,&pixel);
+      AssociateAlphaPixel(&cube,q+u,&pixel);
       if (x > 0)
         {
           pixel.red+=7*current[u-v].red/16;
           pixel.green+=7*current[u-v].green/16;
           pixel.blue+=7*current[u-v].blue/16;
-          if (cube_info->associate_alpha != MagickFalse)
+          if (cube.associate_alpha != MagickFalse)
             pixel.opacity+=7*current[u-v].opacity/16;
         }
       if (y > 0)
@@ -1425,35 +1534,30 @@ static MagickBooleanType FloydSteinbergDither(Image *image,CubeInfo *cube_info)
               pixel.red+=previous[u+v].red/16;
               pixel.green+=previous[u+v].green/16;
               pixel.blue+=previous[u+v].blue/16;
-              if (cube_info->associate_alpha != MagickFalse)
+              if (cube.associate_alpha != MagickFalse)
                 pixel.opacity+=previous[u+v].opacity/16;
             }
           pixel.red+=5*previous[u].red/16;
           pixel.green+=5*previous[u].green/16;
           pixel.blue+=5*previous[u].blue/16;
-          if (cube_info->associate_alpha != MagickFalse)
+          if (cube.associate_alpha != MagickFalse)
             pixel.opacity+=5*previous[u].opacity/16;
           if (x > 0)
             {
               pixel.red+=3*previous[u-v].red/16;
               pixel.green+=3*previous[u-v].green/16;
               pixel.blue+=3*previous[u-v].blue/16;
-              if (cube_info->associate_alpha != MagickFalse)
+              if (cube.associate_alpha != MagickFalse)
                 pixel.opacity+=3*previous[u-v].opacity/16;
             }
         }
       pixel.red=(MagickRealType) ClampToUnsignedQuantum(pixel.red);
       pixel.green=(MagickRealType) ClampToUnsignedQuantum(pixel.green);
       pixel.blue=(MagickRealType) ClampToUnsignedQuantum(pixel.blue);
-      if (cube_info->associate_alpha != MagickFalse)
+      if (cube.associate_alpha != MagickFalse)
         pixel.opacity=(MagickRealType) ClampToUnsignedQuantum(pixel.opacity);
-      i=(ssize_t) ((ScaleQuantumToChar(ClampToUnsignedQuantum(pixel.red)) >> CacheShift) |
-        (ScaleQuantumToChar(ClampToUnsignedQuantum(pixel.green)) >> CacheShift) << 6 |
-        (ScaleQuantumToChar(ClampToUnsignedQuantum(pixel.blue)) >> CacheShift) << 12);
-      if (cube_info->associate_alpha != MagickFalse)
-        i|=((ScaleQuantumToChar(ClampToUnsignedQuantum(pixel.opacity)) >> CacheShift)
-          << 18);
-      if (p->cache[i] < 0)
+      i=CacheOffset(&cube,&pixel);
+      if (cube.cache[i] < 0)
         {
           register NodeInfo
             *node_info;
@@ -1464,10 +1568,10 @@ static MagickBooleanType FloydSteinbergDither(Image *image,CubeInfo *cube_info)
           /*
             Identify the deepest node containing the pixel's color.
           */
-          node_info=p->root;
+          node_info=cube.root;
           for (index=MaxTreeDepth-1; (ssize_t) index > 0; index--)
           {
-            id=ColorToNodeId(cube_info,&pixel,index);
+            id=ColorToNodeId(&cube,&pixel,index);
             if (node_info->child[id] == (NodeInfo *) NULL)
               break;
             node_info=node_info->child[id];
@@ -1475,45 +1579,54 @@ static MagickBooleanType FloydSteinbergDither(Image *image,CubeInfo *cube_info)
           /*
             Find closest color among siblings and their children.
           */
-          p->target=pixel;
-          p->distance=(MagickRealType) (4.0*(QuantumRange+1.0)*(QuantumRange+
+          cube.target=pixel;
+          cube.distance=(MagickRealType) (4.0*(QuantumRange+1.0)*(QuantumRange+
             1.0)+1.0);
-          ClosestColor(image,p,node_info->parent);
-          p->cache[i]=(ssize_t) p->color_number;
+          ClosestColor(image,&cube,node_info->parent);
+          cube.cache[i]=(ssize_t) cube.color_number;
         }
       /*
         Assign pixel to closest colormap entry.
       */
-      index=(size_t) p->cache[i];
+      index=(size_t) cube.cache[i];
       if (image->storage_class == PseudoClass)
         indexes[u]=(IndexPacket) index;
-      if (cube_info->quantize_info->measure_error == MagickFalse)
+      if (cube.quantize_info->measure_error == MagickFalse)
         {
           (q+u)->red=image->colormap[index].red;
           (q+u)->green=image->colormap[index].green;
           (q+u)->blue=image->colormap[index].blue;
-          if (cube_info->associate_alpha != MagickFalse)
+          if (cube.associate_alpha != MagickFalse)
             (q+u)->opacity=image->colormap[index].opacity;
         }
       if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
-        return(MagickFalse);
+        status=MagickFalse;
       /*
         Store the error.
       */
-      AssociateAlphaPixel(cube_info,image->colormap+index,&color);
+      AssociateAlphaPixel(&cube,image->colormap+index,&color);
       current[u].red=pixel.red-color.red;
       current[u].green=pixel.green-color.green;
       current[u].blue=pixel.blue-color.blue;
-      if (cube_info->associate_alpha != MagickFalse)
+      if (cube.associate_alpha != MagickFalse)
         current[u].opacity=pixel.opacity-color.opacity;
-      proceed=SetImageProgress(image,DitherImageTag,p->offset,p->span);
-      if (proceed == MagickFalse)
-        return(MagickFalse);
-      p->offset++;
+      if (image->progress_monitor != (MagickProgressMonitor) NULL)
+        {
+          MagickBooleanType
+            proceed;
+
+#if defined(MAGICKCORE_OPENMP_SUPPORT)
+          #pragma omp critical (MagickCore_FloydSteinbergDither)
+#endif
+          proceed=SetImageProgress(image,DitherImageTag,(MagickOffsetType) y,
+            image->rows);
+          if (proceed == MagickFalse)
+            status=MagickFalse;
+        }
     }
   }
-  scanlines=(RealPixelPacket *) RelinquishMagickMemory(scanlines);
   image_view=DestroyCacheView(image_view);
+  pixels=DestroyPixelThreadSet(pixels);
   return(MagickTrue);
 }
 
@@ -1637,12 +1750,12 @@ static MagickBooleanType RiemersmaDither(Image *image,CacheView *image_view,
       register IndexPacket
         *restrict indexes;
 
-      register ssize_t
-        i;
-
       register PixelPacket
         *restrict q;
 
+      register ssize_t
+        i;
+
       /*
         Distribute error.
       */
@@ -1665,12 +1778,7 @@ static MagickBooleanType RiemersmaDither(Image *image,CacheView *image_view,
       pixel.blue=(MagickRealType) ClampToUnsignedQuantum(pixel.blue);
       if (cube_info->associate_alpha != MagickFalse)
         pixel.opacity=(MagickRealType) ClampToUnsignedQuantum(pixel.opacity);
-      i=(ssize_t) ((ScaleQuantumToChar(ClampToUnsignedQuantum(pixel.red)) >> CacheShift) |
-        (ScaleQuantumToChar(ClampToUnsignedQuantum(pixel.green)) >> CacheShift) << 6 |
-        (ScaleQuantumToChar(ClampToUnsignedQuantum(pixel.blue)) >> CacheShift) << 12);
-      if (cube_info->associate_alpha != MagickFalse)
-        i|=((ScaleQuantumToChar(ClampToUnsignedQuantum(pixel.opacity)) >> CacheShift)
-          << 18);
+      i=CacheOffset(cube_info,&pixel);
       if (p->cache[i] < 0)
         {
           register NodeInfo
@@ -1690,6 +1798,7 @@ static MagickBooleanType RiemersmaDither(Image *image,CacheView *image_view,
               break;
             node_info=node_info->child[id];
           }
+          node_info=node_info->parent;
           /*
             Find closest color among siblings and their children.
           */
@@ -1769,7 +1878,7 @@ static MagickBooleanType DitherImage(Image *image,CubeInfo *cube_info)
   size_t
     depth;
 
-  if (cube_info->quantize_info->dither_method == FloydSteinbergDitherMethod)
+  if (cube_info->quantize_info->dither_method != RiemersmaDitherMethod)
     return(FloydSteinbergDither(image,cube_info));
   /*
     Distribute quantization error along a Hilbert curve.
@@ -1837,16 +1946,16 @@ static CubeInfo *GetCubeInfo(const QuantizeInfo *quantize_info,
     sum,
     weight;
 
-  size_t
-    length;
-
   register ssize_t
     i;
 
+  size_t
+    length;
+
   /*
     Initialize tree to describe color cube_info.
   */
-  cube_info=(CubeInfo *) AcquireAlignedMemory(1,sizeof(*cube_info));
+  cube_info=(CubeInfo *) AcquireMagickMemory(sizeof(*cube_info));
   if (cube_info == (CubeInfo *) NULL)
     return((CubeInfo *) NULL);
   (void) ResetMagickMemory(cube_info,0,sizeof(*cube_info));
@@ -1946,7 +2055,7 @@ static NodeInfo *GetNodeInfo(CubeInfo *cube_info,const size_t id,
       /*
         Allocate a new queue of nodes.
       */
-      nodes=(Nodes *) AcquireAlignedMemory(1,sizeof(*nodes));
+      nodes=(Nodes *) AcquireMagickMemory(sizeof(*nodes));
       if (nodes == (Nodes *) NULL)
         return((NodeInfo *) NULL);
       nodes->nodes=(NodeInfo *) AcquireQuantumMemory(NodesInAList,
@@ -2018,9 +2127,6 @@ MagickExport MagickBooleanType GetImageQuantizeError(Image *image)
   IndexPacket
     *indexes;
 
-  ssize_t
-    y;
-
   MagickRealType
     alpha,
     area,
@@ -2033,6 +2139,9 @@ MagickExport MagickBooleanType GetImageQuantizeError(Image *image)
   size_t
     index;
 
+  ssize_t
+    y;
+
   assert(image != (Image *) NULL);
   assert(image->signature == MagickSignature);
   if (image->debug != MagickFalse)
@@ -2136,7 +2245,7 @@ MagickExport void GetQuantizeInfo(QuantizeInfo *quantize_info)
 %                                                                             %
 %                                                                             %
 %                                                                             %
-%   P o s t e r i z e I m a g e                                               %
+%     P o s t e r i z e I m a g e C h a n n e l                               %
 %                                                                             %
 %                                                                             %
 %                                                                             %
@@ -2149,6 +2258,9 @@ MagickExport void GetQuantizeInfo(QuantizeInfo *quantize_info)
 %
 %      MagickBooleanType PosterizeImage(Image *image,const size_t levels,
 %        const MagickBooleanType dither)
+%      MagickBooleanType PosterizeImageChannel(Image *image,
+%        const ChannelType channel,const size_t levels,
+%        const MagickBooleanType dither)
 %
 %  A description of each parameter follows:
 %
@@ -2157,109 +2269,151 @@ MagickExport void GetQuantizeInfo(QuantizeInfo *quantize_info)
 %    o levels: Number of color levels allowed in each channel.  Very low values
 %      (2, 3, or 4) have the most visible effect.
 %
-%    o dither: Set this integer value to something other than zero to
-%      dither the mapped image.
+%    o dither: Set this integer value to something other than zero to dither
+%      the mapped image.
 %
 */
-MagickExport MagickBooleanType PosterizeImage(Image *image,
-  const size_t levels,const MagickBooleanType dither)
+
+static inline ssize_t MagickRound(MagickRealType x)
 {
-  CacheView
-    *posterize_view;
+  /*
+    Round the fraction to nearest integer.
+  */
+  if (x >= 0.0)
+    return((ssize_t) (x+0.5));
+  return((ssize_t) (x-0.5));
+}
 
-  ExceptionInfo
-    *exception;
+MagickExport MagickBooleanType PosterizeImage(Image *image,const size_t levels,
+  const MagickBooleanType dither)
+{
+  MagickBooleanType
+    status;
 
-  Image
-    *posterize_image;
+  status=PosterizeImageChannel(image,DefaultChannels,levels,dither);
+  return(status);
+}
 
-  IndexPacket
-    *indexes;
+MagickExport MagickBooleanType PosterizeImageChannel(Image *image,
+  const ChannelType channel,const size_t levels,const MagickBooleanType dither)
+{
+#define PosterizeImageTag  "Posterize/Image"
+#define PosterizePixel(pixel) (Quantum) (QuantumRange*(MagickRound( \
+  QuantumScale*pixel*(levels-1)))/MagickMax((ssize_t) levels-1,1))
 
-  ssize_t
-    j,
-    k,
-    l,
-    length,
-    n;
+  CacheView
+    *image_view;
+
+  ExceptionInfo
+    *exception;
 
   MagickBooleanType
     status;
 
+  MagickOffsetType
+    progress;
+
   QuantizeInfo
     *quantize_info;
 
   register ssize_t
     i;
 
-  register PixelPacket
-    *restrict q;
+  ssize_t
+    y;
 
-  /*
-    Posterize image.
-  */
   assert(image != (Image *) NULL);
   assert(image->signature == MagickSignature);
   if (image->debug != MagickFalse)
     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
-  posterize_image=AcquireImage((ImageInfo *) NULL);
-  if (posterize_image == (Image *) NULL)
-    return(MagickFalse);
-  l=1;
-  length=levels*levels*levels;
-  while ((l*l*l) < (ssize_t) MagickMin((ssize_t) length,MaxColormapSize+1))
-    l++;
-  status=SetImageExtent(posterize_image,(size_t) (l*l*l),1);
-  if (status == MagickFalse)
-    {
-      posterize_image=DestroyImage(posterize_image);
-      return(MagickFalse);
-    }
-  status=AcquireImageColormap(posterize_image,levels*levels*levels);
-  if (status == MagickFalse)
+  if (image->storage_class == PseudoClass)
+#if defined(MAGICKCORE_OPENMP_SUPPORT)
+  #pragma omp parallel for schedule(dynamic,4) shared(progress,status)
+#endif
+    for (i=0; i < (ssize_t) image->colors; i++)
     {
-      posterize_image=DestroyImage(posterize_image);
-      return(MagickFalse);
+      /*
+        Posterize colormap.
+      */
+      if ((channel & RedChannel) != 0)
+        image->colormap[i].red=PosterizePixel(image->colormap[i].red);
+      if ((channel & GreenChannel) != 0)
+        image->colormap[i].green=PosterizePixel(image->colormap[i].green);
+      if ((channel & BlueChannel) != 0)
+        image->colormap[i].blue=PosterizePixel(image->colormap[i].blue);
+      if ((channel & OpacityChannel) != 0)
+        image->colormap[i].opacity=PosterizePixel(image->colormap[i].opacity);
     }
-  posterize_view=AcquireCacheView(posterize_image);
+  /*
+    Posterize image.
+  */
+  status=MagickTrue;
+  progress=0;
   exception=(&image->exception);
-  q=QueueCacheViewAuthenticPixels(posterize_view,0,0,posterize_image->columns,1,
-    exception);
-  if (q == (PixelPacket *) NULL)
-    {
-      posterize_view=DestroyCacheView(posterize_view);
-      posterize_image=DestroyImage(posterize_image);
-      return(MagickFalse);
-    }
-  indexes=GetCacheViewAuthenticIndexQueue(posterize_view);
-  n=0;
-  for (i=0; i < l; i++)
-    for (j=0; j < l; j++)
-      for (k=0; k < l; k++)
+  image_view=AcquireCacheView(image);
+#if defined(MAGICKCORE_OPENMP_SUPPORT)
+  #pragma omp parallel for schedule(dynamic,4) shared(progress,status)
+#endif
+  for (y=0; y < (ssize_t) image->rows; y++)
+  {
+    register IndexPacket
+      *restrict indexes;
+
+    register PixelPacket
+      *restrict q;
+
+    register ssize_t
+      x;
+
+    if (status == MagickFalse)
+      continue;
+    q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
+    if (q == (PixelPacket *) NULL)
       {
-        posterize_image->colormap[n].red=(Quantum) (QuantumRange*i/
-          MagickMax(l-1L,1L));
-        posterize_image->colormap[n].green=(Quantum)
-          (QuantumRange*j/MagickMax(l-1L,1L));
-        posterize_image->colormap[n].blue=(Quantum) (QuantumRange*k/
-          MagickMax(l-1L,1L));
-        posterize_image->colormap[n].opacity=OpaqueOpacity;
-        *q++=posterize_image->colormap[n];
-        indexes[n]=(IndexPacket) n;
-        n++;
+        status=MagickFalse;
+        continue;
       }
-  if (SyncCacheViewAuthenticPixels(posterize_view,exception) == MagickFalse)
+    indexes=GetCacheViewAuthenticIndexQueue(image_view);
+    for (x=0; x < (ssize_t) image->columns; x++)
     {
-      posterize_view=DestroyCacheView(posterize_view);
-      posterize_image=DestroyImage(posterize_image);
-      return(MagickFalse);
+      if ((channel & RedChannel) != 0)
+        q->red=PosterizePixel(q->red);
+      if ((channel & GreenChannel) != 0)
+        q->green=PosterizePixel(q->green);
+      if ((channel & BlueChannel) != 0)
+        q->blue=PosterizePixel(q->blue);
+      if (((channel & OpacityChannel) != 0) &&
+          (image->matte == MagickTrue))
+        q->opacity=PosterizePixel(q->opacity);
+      if (((channel & IndexChannel) != 0) &&
+          (image->colorspace == CMYKColorspace))
+        indexes[x]=PosterizePixel(indexes[x]);
+      q++;
     }
-  posterize_view=DestroyCacheView(posterize_view);
+    if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
+      status=MagickFalse;
+    if (image->progress_monitor != (MagickProgressMonitor) NULL)
+      {
+        MagickBooleanType
+          proceed;
+
+#if defined(MAGICKCORE_OPENMP_SUPPORT)
+  #pragma omp critical (MagickCore_PosterizeImageChannel)
+#endif
+        proceed=SetImageProgress(image,PosterizeImageTag,progress++,
+          image->rows);
+        if (proceed == MagickFalse)
+          status=MagickFalse;
+      }
+  }
+  image_view=DestroyCacheView(image_view);
   quantize_info=AcquireQuantizeInfo((ImageInfo *) NULL);
+  quantize_info->number_colors=(size_t) MagickMin((ssize_t) levels*levels*
+    levels,MaxColormapSize+1);
   quantize_info->dither=dither;
-  status=RemapImage(quantize_info,image,posterize_image);
+  quantize_info->tree_depth=MaxTreeDepth;
+  status=QuantizeImage(quantize_info,image);
   quantize_info=DestroyQuantizeInfo(quantize_info);
-  posterize_image=DestroyImage(posterize_image);
   return(status);
 }
 \f
@@ -2452,9 +2606,6 @@ static MagickBooleanType DirectToColormapImage(Image *image,
   CacheView
     *image_view;
 
-  ssize_t
-    y;
-
   MagickBooleanType
     status;
 
@@ -2464,6 +2615,9 @@ static MagickBooleanType DirectToColormapImage(Image *image,
   size_t
     number_colors;
 
+  ssize_t
+    y;
+
   status=MagickTrue;
   number_colors=(size_t) (image->columns*image->rows);
   if (AcquireImageColormap(image,number_colors) == MagickFalse)
@@ -3026,13 +3180,13 @@ extern "C" {
 
 static int IntensityCompare(const void *x,const void *y)
 {
-  ssize_t
-    intensity;
-
   PixelPacket
     *color_1,
     *color_2;
 
+  ssize_t
+    intensity;
+
   color_1=(PixelPacket *) x;
   color_2=(PixelPacket *) y;
   intensity=PixelIntensityToQuantum(color_1)-(ssize_t)
@@ -3052,21 +3206,19 @@ static MagickBooleanType SetGrayscaleImage(Image *image)
   ExceptionInfo
     *exception;
 
-  ssize_t
-    j,
-    y;
+  MagickBooleanType
+    status;
 
   PixelPacket
     *colormap;
 
-  ssize_t
-    *colormap_index;
-
   register ssize_t
     i;
 
-  MagickBooleanType
-    status;
+  ssize_t
+    *colormap_index,
+    j,
+    y;
 
   assert(image != (Image *) NULL);
   assert(image->signature == MagickSignature);
@@ -3099,12 +3251,12 @@ static MagickBooleanType SetGrayscaleImage(Image *image)
         register IndexPacket
           *restrict indexes;
 
-        register ssize_t
-          x;
-
         register const PixelPacket
           *restrict q;
 
+        register ssize_t
+          x;
+
         if (status == MagickFalse)
           continue;
         q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
@@ -3175,12 +3327,12 @@ static MagickBooleanType SetGrayscaleImage(Image *image)
     register IndexPacket
       *restrict indexes;
 
-    register ssize_t
-      x;
-
     register const PixelPacket
       *restrict q;
 
+    register ssize_t
+      x;
+
     if (status == MagickFalse)
       continue;
     q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);